1. Field of the Invention
The present invention relates to a laser printer apparatus and, more specifically, to a laser printer apparatus including a laser scanning unit.
2. Description of the Background Art
A laser printer apparatus is one type of printer apparatuses. As can be seen from FIG. 8, in a laser printer apparatus 101, a prescribed sheet of paper 120 fed from a paper feed inlet 113 of laser printer apparatus 101 passes through a photoreceptor 102, while the photoreceptor 102 is irradiated with a prescribed laser beam in accordance with an image signal, by a laser scanning unit 104. Consequently, toner is transferred to the sheet of paper 120. The sheet of paper 120 on which the toner has been transferred has its toner fixed in a fixing unit 105, and then the sheet is discharged from a discharge outlet 114. In this type of laser printer apparatus 101, a cartridge 103 containing the toner to be supplied to the photoreceptor 102 is taken in and out through a prescribed door for maintenance, and after it is detected by a prescribed detecting portion (not shown) that cartridge 103 is attached to laser printer apparatus 101, a prescribed printing operation takes place.
In laser printer apparatus 101, as a framework of laser printer body, a pair of frames (not shown) are arranged to be opposite to each other. Cartridge 103, photoreceptor 102, fixing unit 105 and laser scanning unit 104 are respectively arranged at prescribed positions within the pair of frames. A motor (not shown) for driving laser printer apparatus 101, including feeding of the sheet of paper 120 (represented by a dotted arrow), is arranged at a prescribed position outside the pair of frames. A substrate portion (not shown) controlling operations of laser printer apparatus 101 is arranged outer than one of the pair of frames. The substrate is electrically connected to the detecting portion detecting attachment of cartridge 103 through a prescribed wire. Japanese Utility Model Registration No. 3085412 discloses an example of the wiring structure in the laser printer apparatus.
The conventional laser printer apparatus, however, has the following problems. Laser printer apparatus 101 has been made smaller and smaller and in that course, it becomes desirable to arrange the motor within the pair of frames. When the motor is to be arranged within the pair of frames, the motor must be placed close to cartridge 103 while not interfering the operation of putting-in or taking-out cartridge 103 at the time of maintenance.
If the motor were placed close to cartridge 103, however, a wire connecting the sensor detecting the cartridge 103 to the substrate would be affected by the heat from the motor. If the wire were positioned to avoid the influence of heat from the motor, the wire would be closer to the fixing unit. The fixing unit fixes at a temperature of about 200° C., and therefore, the wire would be affected by the heat from the fixing unit. If the wire is formed of a wire material having high heat resistance in order to avoid the influence of heat, the cost increases, and if the wire is routed to avoid both the motor and the fixing unit, the wire length becomes long and the wire would be more susceptible to noise.